The invention pertains to event detection systems which include predefined groups of event detectors. More particularly, the invention pertains to such systems wherein groups can be automatically defined independently of specific detectors that might be installed in the system.
Event detection systems, such as burglar or fire alarm systems have been recognized as being useful in providing warnings of the existence of events of interest such as intrusion or fire. One known form of such a system is disclosed in Tice et al. U.S. Pat. No. 4,916,432 entitled xe2x80x9cSmoke and Fire Detection Communicationxe2x80x9d and assigned to the assignee hereof. The Tice patent is hereby incorporated by reference herein.
In such systems, it has been recognized that it is at times advantageous to group detectors for processing purposes. One known approach is to load group information into detectors. It can also be loaded into the system control panel, assuming that the system has such a panel.
One group might include all detectors on a given floor of the building. Another group might all detectors in a portion of a floor of a building.
Grouping detectors together makes it possible to take into account the particular physical characteristics of the region of the building being monitored. It is also known to couple groups of detectors, via a communication link, to a common control element which might include one or more programmed processors. The control element receives information from the detectors for the purpose of determining if a fire profile is being reported via detector or by a group of detectors.
One system which illustrates the use of groupings is disclosed and claimed in U.S. Pat. No. 5,539,389 entitled Device Group Communication for Fire, Security and Control Systems assigned to the assignee hereof. The disclosure of the ""389 patent is incorporated herein by reference.
In such systems it is also known to from time to time remove and replace detectors for service or maintenance purposes. In such situations, group information might have to be loaded into the replacement detector or detectors. Alternately, when a system is being installed, group information must be supplied to the control panel.
It would be desirable to be able to supply group information to the panel substantially automatically. It would also be desirable to replace detectors without either losing group information or having to load the replacement detectors with group information.
It is also been recognized that since monitoring systems may include significant numbers of detectors that it is desirable for the system to carry out automatic address assignment to detectors being installed in the system. One form of automatic addressing is disclosed in Tice pending United States patent application entitled Electronic Self-Locating System and Method filed May 19, 1997, Ser. No. 08/858,625. The disclosure of the Tice application is incorporated herein by reference.
It would be desirable to be able to maximize the cost effectiveness and the efficiency benefits achieved by automatic addressing systems by minimizing the labor required to define groups of detectors for the control element. Preferably, it would be possible to automatically define groups, once addresses were automatically assigned. Also, it would be preferable if the introduction of automatic group definition did not require a substantial additional, hence expensive, hardware and software.
Group defining devices can be attached to electrical units at the time of installation. Such devices enable a common control unit, coupled to the electrical units via a communications link, to determine logical groupings of devices. This promotes simplified installation of the system.
Groups can be automatically defined in an event detection system by coupling a group marker to a base of a boundary detector for the group. For example, a group end marker could be coupled to the base of the appropriate detector. Replacing the detector does not alter the location of such end markers.
End markers can be implemented with electronic components coupled to the bases of respective detectors. Exemplary markers include switches, resistors or capacitors. Other components, including mechanical members mounted in the base or bases could be used without limitation.
In one aspect, both start and end markers could be used. Alternately, only start markers need be used.
At installation, the system control panel can carry out any one of the known automatic addressing methods, such as the method disclosed in the above-noted Tice U.S. Application. Such systems usually inform the control panel of the topology of the detectors coupled to the system.
Once the control element has information, automatically obtained, concerning detector topology The group marker or markers automatically define the groups even in the presence of replacement detectors installed after the fact.
In one aspect, an electrical element can be coupled to at least one electrical unit which, relative to a communications link, defines a boundary of the group. This element can be coupled to the respective electrical unit in a variety of ways. All that is required is that the respective electrical unit be able to sense that it is a group boundary establishing unit. In one embodiment, the element can be coupled to a base which removably receives a detector.
In yet another aspect, group boundaries can be established by coupling a detectable boundary identifying element such as a resistor or a switch to a boundary defining electrical unit. The presence of this element can be sensed by the electrical unit. This information can be provided to the control element in response to an appropriate command. The control element can in turn use the information to define which electrical units are associated with which group.
One resistor, for example, with respect to a first electrical unit, signifies one boundary of the group, relative to the communication link. Another resistor, relative to the second electrical unit defines the other boundary.
In yet another aspect, the topology can be used to define the group or groups. For example, a group could be defined as including all detectors on a pair of communications lines coupled directly, or indirectly, to the control element. A different pair of lines could define another group which includes all detectors coupled to the different pair of lines. In this embodiment, group definition can be effected without the attachment of group markers to detector bases.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.